I just downloaded the Inline-C tar.gzAs
Anonymous Monk said, that's not the correct way.
However, because Inline::C is, itself, a pure perl module that approach will work - but you didn't do it correctly. As well as copying the "C" folder to perl/site/lib/Inline, you should also copy C.pm and C.pod to the same location.
Most people would install Inline::C by running something like
cpan -i Inline::C
Alternatively, having already downloaded and extracted Inline-C-0.62.tar.gz you could 'cd' to the extracted Inline-C-0.62 folder and run 'perl Makefile.PL', 'dmake test', then 'dmake install'.
If you go down either of those 2 paths, expect to see lots of warnings (with I::C-0.62) during the 'dmake test' phase - and expect t/26fork.t and t/27inline_maker.t to fail. (But just do the 'dmake install' anyway.)
Nearly forgot - for running dmake test you'll need Test::Warn (and its preprequisites) and File::Copy::Recursive installed.
Cheers,
Rob